It seems like a very natural feature that should be a part of the program

I disagree. Unless your PDF were to contain native Illustrator data (which it won't, if created elsewhere or saved without this option from AI) working with such files would be a nightmare - text disapepars or gets converted, there are no layers, stuff gets rasterized, colors shift. Even if you just want to change one page, you'd still suffer the limitations laid out above and your newly created/ updated PDF might not turn out as what you expected at all. AI simply doesn't understand things like structure or semantics. So in all fairness, long before such a feature would have any priority, AI would have to be much smarter in other departments regardless of whether you edit just one page or a whole book and even then there may be limitations - PDF, first and foremost is a delivery/ archival format not meant to be re-edited in the first place. That people do it all the time and want better ways of hacking is a whole different matter... Anyway, no, you're not missing anything. If you wanna hack it, using that script or opening/ placing the PDF page by page is your only option.

The best way to open a multipage PDF is with Acrobat or Adobe Reader. You can easily place a multipage PDF into InDesign, however you cannot edit the PDF in InDesign. You can add elements to your InDesign pages and then export to a new PDF. In InDesign CS5 the fastest way to place a multipage PDF is Window> Utilities> Scripts> Multipageimporter (double click). You can do some limited editing to your PDF in Acrobat, or you can use PitStop or some other plugin to do more extensive editing, but it's always best to go back to the program that created the PDF and make your edits there.

It might, it might not. The same limitations apply as I laid them out for AI. As Luke already said, it's always gonna be a hack of sorts, if there is no "program native" data appended to the original PDF, meaning essentially an embedded backup copy of your AI or INDD file. Again, PDF was never meant or designed to be editable beyond certain limits and depending on what content from the PDF you actualyl need, it may be easier to rebuild it from scratch or request access to the original files rather than e.g. trying to separate text that has been fused with a background image the hard way. Really depends on what exactly you plan on doing which you haven't told us yet...

I have received a 8 page catalog. The company received the catalog from their partner. I am to place a company logo and address into this pdf.

I opened it up in Illustrator using the plugin I mentioned above and it seemed to work alright. But there are missing fonts that creates some havoc for me. Another solution I just did now is to open the pdf in Photoshop as pages. I am about to put the logo and address on the first page and save the page. I will also need to save all the other pages as probably tif or psd files. Go to bridge select all the pages and output to pdf.

That is where I am right now. If anyone has a better idea on how to do this please let me know.

If ou only need to add something (and not edit), do as already mentioned and place the catalog in an InDesign file, then place your logo and text and export another PDF. You can also place it in Illustrator, but don't open it.

I think Monika's suggestion would be most efficient and due to how ID embeds placed object probably also retain most of the existing data as vectors and native text. Rasterizing in PS also is of course a way of doing things, but keep in mind that the new PDF may never be as small as probably the original one was, which could be something to consider for online distribution. And of course you completely lose accessibility/ screen reading ability, since there is no text, just one page sized image essentially. If that's of no concern, you could proceed in that direction as well.

I placed it into Illustrator and had problems with fonts that I did not have. (Thank you for the idea of placing the pdf file into Illustrator, and thank you for the other information!)

So I took the pages into Photoshop and added the logo and some text there. Saved each page and brought it into Bridge and saved the pages into a pdf file.

I received a question about further editing, and replied that yes Illustrator (and probably Indesign as well) can edit the contents of a pdf but I will need to have the original fonts or else I will need to find similar that I have in my system today. Tomorrow I will probably get a few more pdf files that I am this time to edit.

Don't embed it when placing into Illustrator and you won't have problems with fonts. What you did when opening it in Photoshop is rasterizing it. Especially text elements that have been in the PDF will suffer a lot from rasterizing, because a resolution of about 300 ppi is way too low for crisp text.

the artboard feature is relatively new and when first introduced it was not envisioned as a page type of tool but a way of exporting areas of the canvas as a file for various uses.

When it was pointed out that this was essenailly the same as a page type tool it became a multi-purpose tool, once that happened then it was pointed out that it would be a good idea to allow one to organize, renumber and export as individual files and some other features.

Master artboards are not yet available and placing mutilple page pdf as multiple artboard documents are also not here yet but it might be in the future. It would make a lot of sense as you point out.

But if Adobe did this for AI then they would probably be compelled to bring editting capabilities to pdfs placed in ID and that might be a big task. So it might take sometime for this to happened.

Of course it may never happen.

I think it would help AI and ID if AI alone had this capability and AI files could then be smart objects in ID.

I went back and redid what I had done in Photoshop. (Yesterday I brought in the pdfs, modified them and saved them as psd files. Opened Bridge saved the psd(s) as pdf files.) This time I placed (linked) them one at a time in Illustrator. Created extra artboards for multipage pdf files where it was needed. Added the logos, and saved the pdf files. I also had to with two files today hide some text by placing a white rectangle on top of it and then add another text. And save it as pdf files again. It felt a lot smoother today since I knew what I was doing. Yesterday became the experimenting day for this, so it was good to feel the speed I did this today.